Method and apparatus for clamping and manipulating workpieces during a sewing operation

Abstract

The present invention relates to a method and apparatus for clamping and manipulating clothing components with respect to a double needle sewing machine so as to automatically attach and finish stitch a left fly to a front panel of a jeans style garment. The apparatus includes a work holding carriage which translates along a path generally perpendicular to a plane containing dual sewing machine needles. A pair of rotatable discs which are mounted on the carriage in nested fashion and rotate about spaced apart centers of rotation. The axes for the centers of rotation extend substantially perpendicular to the carriage and generally parallel to the dual sewing machine needles. The invention not only encompasses a method for carrying out the sewing operations, but also an apparatus including a drive mechanism for the traversing carriage, a rotating mechanism for each of the nested rotating discs and a clamping apparatus for holding and positioning the assembled fly with respect to the jeans panel.

What is claimed is: 
     
       1. Apparatus for clamping and manipulating a plurality of clothing components relative to a sewing machine having reciprocating sewing needle means comprising: (a) work table means operatively associated with the sewing machine;   (b) clamping means to hold the plurality of clothing components in a desired orientation on the work table means and;   (c) drive means operatively interconnected with the work table means to move the work table means with respect to the sewing machine means such that the plurality of clothing components are translated and rotated with respect to the reciprocating sewing needle means so as to attach the components together with a line of stitches, a portion of said line having at least a constant curved portion with a radius r .   
     
     
       2. The apparatus according to claim 1 wherein the work table means comprises: (a) a carriage defining a work surface;   (b) means to support the carriage such that it may translate with respect to the sewing needle means; and   (c) disc means rotatably attached to the carriage, said drive means including means to rotate the disc means with respect to the carriage.   
     
     
       3. The apparatus according to claim 2 wherein the disc means comprises: (a) a first disc rotatably mounted on the carriage, the first disc defining a work surface substantially coplanar with the work surface of the carriage and being rotatable about a first axis of rotation; and,   (b) a second disc rotatably mounted on the carriage, the second disc defining a work surface substantially coplanar with the work surface of the first disc and being rotatable about a second axis of rotation.   
     
     
       4. The apparatus according to claim 3 wherein the first and second axes of rotation extend substantially parallel to each other and to the reciprocating sewing needle means. 
     
     
       5. The apparatus according to claim 4 wherein the first and second axes of rotation are laterally spaced apart a distance d such that d is substantially equal to the radius r of the curved portion of the stitch. 
     
     
       6. The apparatus according to claim 2 wherein the clamping means comprises: (a) a first clamping device to hold a first clothing component on a work surface of the disc means; and,   (b) a second clamping device to hold a second clothing component against the first clothing component in a plurality of positions.   
     
     
       7. The apparatus according to claim 6 wherein: (a) the disc means comprises: (i) a first disc rotatably mounted on the carriage, the first disc defining a work surface substantially coplanar with the work surface of the carriage and being rotatable about a first axis of rotation; and,   (ii) a second disc rotatably mounted on the carriage, the second disc defining a work surface substantially coplanar with the work surface of the first disc and being rotatable about a second axis of rotation; and,     (b) the first clamping device comprises a first, generally planar clamping member attached to the second disc and adapted to hold the first clothing component against the work surface of the second disc.   
     
     
       8. The apparatus according to claim 7 wherein the second clamping device comprises: (a) a locating member having guide means to enable an operator to properly position the second clothing component thereon;   (b) a second clamping member mounted on the locating member so as to be movable between an open position and a clamped position; and,   (c) attaching means to attach the locating member to the second disc.   
     
     
       9. The apparatus according to claim 8 further comprising an over-center toggle mechanism in operative relationship with the second clamping member so as to bias the member in either the open or clamped positions. 
     
     
       10. The apparatus according to claim 8 wherein the guide means comprises: (a) a guide slot defined by the locating member and adapted to receive a first portion of the second clothing component; and,   (b) a guide surface on the locating member adapted to locate a second portion of the second clothing component with respect to the second clamping member.   
     
     
       11. The apparatus according to claim 8 wherein the attaching means comprises: (a) a main shaft having a longitudinal axis and operatively supporting the locating member;   (b) mounting means to mount the main shaft on the second disc such that the shaft may translate relative to the second disc in a direction generally perpendicular to its longitudinal axis;   (c) first actuation means operatively connected to the main shaft so as to translate the shaft generally perpendicular to its longitudinal axis; and,   (d) second actuation means operatively connected to the second clamping device to cause the second clamping device to oscillate about the longitudinal axis of the main shaft.   
     
     
       12. The apparatus according to claim 11 comprising a plurality of second clamping devices mounted on the main shaft. 
     
     
       13. The apparatus according to claim 12 further comprising means to interconnect the plurality of second clamping devices such that all oscillate in unison. 
     
     
       14. The apparatus according to claim 13 wherein the interconnecting means comprises a second shaft extending generally parallel to, but laterally spaced from the main shaft and interconnecting the second clamping devices of the second clamping devices. 
     
     
       15. The apparatus according to claim 14 wherein the second actuation means comprises: (a) a bellcrank member attached to the main shaft and the second shaft, and having an actuating arm portion;   (b) actuating cylinder means having an extendable and retractable piston rod; and,   (c) link means interconnecting the piston rod and the actuating arm portion such that extension and retraction of the piston rod causes the second shaft, and the locating members, to oscillate about the longitudinal axis of the main shaft.   
     
     
       16. The apparatus according to claim 15 wherein the second actuation means further comprises: (a) second and third bellcrank members attached to the main shaft and the second shaft;   (b) a first drag link having a first end connected to the second bellcrank member and defining a slot adjacent a second end;   (c) a second drag link having a first end connected to the third bellcrank member and defining a slot adjacent a second end; and,   (d) an axle fixedly attached to the second disc and extending through the slots in the first and second drag links.   
     
     
       17. The apparatus according to claim 2 wherein the drive means comprises: (a) first drive means to cause translation of the carriage with respect to the sewing needle means and to rotate the first disc about a first axis of rotation; and,   (b) second drive means to rotate the second disc about a second axis of rotation.   
     
     
       18. The apparatus according to claim 17 wherein the first drive means comprises means to rotate the first disc through an angle of approximately 90° about the first axis of rotation. 
     
     
       19. The apparatus according to claim 17 wherein the second drive means comprises means to rotate the second disc through an angle of approximately 90° about the second axes of rotation. 
     
     
       20. The apparatus according to claim 19 further comprising means to interlock the first and second discs such that the second disc rotates with the first disc. 
     
     
       21. The apparatus according to claim 20 wherein the first drive means comprises means to rotate the first disc through an angle of approximately 90° about the first axis of rotation. 
     
     
       22. The apparatus according to claim 17 wherein the first drive means comprises: (a) a first control arm pivotally attached to the carriage so as to rotate about the first axis of rotation and connected to the first disc;   (b) actuating means;   (c) a drive member connected to the actuating means;   (d) a first driven element attached to the carriage and the first control arm so as to rotate therewith;   (e) stop means operatively associated with the first driven element to prevent rotation thereof during at least a portion of the travel of the carriage; and   (e) a driving element operatively interconnecting the drive member and the first driven element.   
     
     
       23. The apparatus according to claim 22 wherein the first driven element comprises a first sprocket wheel attached to the first control arm so as to rotate therewith and wherein the driving element comprises a drive chain. 
     
     
       24. The apparatus according to claim 23 wherein the stop means comprises: (a) a second sprocket fixedly attached to the first sprocket wheel;   (b) a third sprocket wheel rotatably attached to the carriage;   (c) an endless drive element operatively interconnecting the second and third sprocket wheels;   (d) first and second guide rails extending generally parallel to each other and to the path of travel of the carriage, the second guide rail being non-continuous in length so as to define a gap;   (e) a guide member fixedly attached to the third sprocket wheel and slidably disposed between the guide rails such that rotation of the first, second and third sprocket wheels is prevented except when the guide member is aligned with the gap defined by the second guide rail.   
     
     
       25. The apparatus according to claim 24 wherein the pitch diameter of the third sprocket wheel is approximately one-half that of the second sprocket wheel. 
     
     
       26. The apparatus according to claim 25 wherein the first control arm moves through an arc of approximately 90°. 
     
     
       27. The apparatus according to claim 26 wherein the second drive means comprises: (a) a second control arm pivotally attached to the carriage so as to rotate about a second axis of rotation and operatively connected to the second disc;   (b) second actuating means operatively interposed between the carriage and the second control arm so as to move the second control arm through an arc of approximately 90°.